The design is skeuomorphic, modeled after a standard bifold wallet which gives your physical cards the same treatment.

My current wallet doesn't give me any affordances: https://grifiti.com/products/grifiti-band-joes-3-25-x-1-25-i...

your current wallet lets you add labels or stickers to your cards.

classic Apple situation - look, this is super clean, intuitive software! but if you want a reasonable level of flexibility that you would expect elsewhere, you are SOL.